WASHINGTON — Key senators struck a bipartisan agreement to extend unemployment insurance for more than 2 million jobless Americans whose benefits have run out, though approval is not certain in the Republican-controlled House.

Thursday's proposal for a five-month continuation of benefits faces a likely filibuster by tea party conservatives in the Senate, pushing votes until later this month after Congress returns from a weeklong recess.

But with five Republican senators joining Democrats in Thursday's agreement, passage in the Senate is expected. That would pressure House Speaker John A. Boehner (R-Ohio) to take up the measure over the objections of hard-line Republicans who believe jobless aid discourages work.

"Restoring this much needed economic lifeline will help job seekers, boost our economy and provide a little certainty," said Sen. Jack Reed (D-R.I.), who brokered the deal with Sen. Dean Heller (R-Nev.). Both lawmakers' states have the nation's highest unemployment rates.

Unemployment insurance for the long-term unemployed was cut off Dec. 28 after Congress could not agree on a compromise to extend the program. Since then, more than 2 million people have lost their aid. Most states offer no more than 26 weeks of assistance.

The nearly $10-billion package would be funded from several sources, including previously approved changes to private pension requirements that increase tax revenues, as well as a continuation of certain fees on customs users.

Boehner's office had no immediate comment, but the issue is important in an election year, especially for lawmakers in states where the unemployment rate remains high. The national rate is 6.7%.

The Senate has tried several times this year to extend jobless aid, but efforts have run into political and procedural resistance from Republicans who are opposed to long-term assistance or want the chance to offer more amendments than Democrats have been willing to accept.